Nocturnal antiaircraft fire control device



Dec. 6, 1938. RHQUSE 2,139,636

NOCTURNAL ANTIAIRCRAFT FIRE CONTROL DEVICE Filed May 21, 1957 5 Sheets-Sheet 1 INVENTOR fggmvn fl. HousE Dec. 6, 1938. R HOUSE 2,139,636

NOGTURNAL ANTIAIRCRAFT FIRE CONTROL DEVICE Filed May 21, 1957 5 Sheets-Sheet INVENTOR FRANK R.HausE HIS Dec. 6, 1938. F R. HOUSE 2,139,636

NOCTURNAL ANTIAIRCRAFT FIRE CONTROL DEVICE I Filed May 21, 1937 5 Sheets-Sheet 3 na -v IN\ IENTOR fgnlvn H. Hot/8E ORNE Dec. 6, 1938. F, R, H E 2,139,636

NOCTURNAL ANTIAIRCRAFT FIRE CONTROL DEVICE Filed May 21, 1957 5 Sheets-Sheet 4 HIS ATTORNEY 6, 9 8- F. R. HOUSE 2,139,636

NOCTURNAL ANTIAIRCRAFT FIRE CONTROL DEVICE Filed May 21, 1937 5 Sheets-Sheet 5 V NTOR IN figgwn .housE M R TTORNEY Patented Dec. 6, 1938 v NOCTURNAL ANTIAIRCRAFT FIRE CON- TROL DEVICE Y Frank R. House, Baldwin Harbor, N. Y., assignor to Sperry Gyroscope Company, Inc., Brooklyn, N. Y., a corporation of New York Application May 21, 1937, Serial No. 144,018

10 Claims. (01. 33-46) This invention relates to nocturnal anti-air- Fig. 8 is a diagram i l r he pr nc p craft fire control devices, especially to the type in involved in the Parallax mechanismwhich sound locators are employed to locate the Fi 8A is a di r m s w n he binoculars craft at night with or without the use of searchmounted adjacent the false target sightlights. My invention also ha more general ap- Fig. 9 is a transverse sectional view similar to 5 plication to fire control against any rapidly movb Showing a modified m of the ining target, even for daylight use. vention.

More particularly, my invention is an improveis a Side View Of this o ment on the type of nocturnal fire control device 11 s a diagram showing the p e n- 1 shown in my prior application; for Univer volved, being a horizontal projection of the tar- 1o anti-aircraft sight, Serial No. 88,082, filed June t Course- 30, 1936. According to this system, a false target Re r i first to Figthe conventional Sound is displaced in a horizontal plane in a direction receiving horns e Shown at I, 2 d Which determined by the movements of the sound 10- m y be on r c ed and arr n ed somewhat as cator in azimuth and elevation, and the amount s w in e aforesaid Drier application 88,032 15 of such displacement is made proportional to the d in greater detail in my P o application ratio of the speed of sound t th estimated Serial No. 66,158, for Sound locator receivers, speed of the target, so that the angle between the filed February 1936- According to this y line of sight as indicated by the sound locator te t sev al h r s ar t d f r turn n and the line of sight on the false target is the together in azimuth 0h framework supported 20 sound lag error angle. from rotatable graduated base-ring 4, and also In such a device, the Searchlight may be 1 for rotation in elevation on a common supportcated at some distance from the sound locator, n 0W Shaft 5 jourhaled in bearings 5 d so that a parallax correction is necessary, and on the framework (see Fig. 3). Scale H5 shows 25 it is one of the objects of this invention to introthe elevation angle w e read 011 index 25 duce such a parallax correction in a simple man- 3), While settle I H the bearingangle (Figner and so that when once introduced, the cor- 1). For rotating t e Sound loeator in a u rection will be varied as the sound locator is I show a ha dw the Operator of ch turned in all planes, so that such correction is wears helmet phones 8 and 9 connected to horns applied properly both as an azimuth and an ele- I and 2 through tubes H0 and I ll. Similarly, 30

vation correction in all positions of the target. the horns are turned in elevation from hand- Other objects of the invention are to simplify wheel ID, the operator of which wears helmet and improve upon the mechanism of the prior ear phones II and I2 connected through suitapplication, particularly as to the construction able sound track tubes ll2-and H3 to horns 2 and operation of the sight itself. and 3, the sound track from the horn 2 being 35 Referring to the drawings, showing one form divided, as shown in my aforesaid prior applimy invention may assume. cation No. 66,158.

Fig. 1 is a diagram illustrating my complete As shown in Fig. 1, the rotation of the handanti-aircraft device. wheel turns the ring or platform 4 through bevel Fig. 2 is a detailed side view showing the pargears l3 and pinion I 4, meshing with an internal 4Q allel linkage mounting of the box on which the gear [5 in said ring. The rotation of the platfalse target is mounted. form in azimuth carries with it, by means of Fig. 3 is a plan view of the central portion of arm IS, the sighting means proper H. In this the device (not showing the sound locating case, the sight is shown as in the form of a fixed 5 horns). eye piece I8 and a reflecting mirror or prism 4 s a ver l section through the con- I!) mounted for movement in elevation on horitrol bOX r t e false target, taken on line zontal trunnions 20 and 20'. Said mirror prefof Fig. 5. erably has suitable cross hairs 2| at the center Fig. 5 is a horizontal section through the thereof, which the operator brings into coincisame,-showing the drive for the rollers which dence with the false target ball 22 by moving 50 revolve the ball. universal control handle 85.

Fig. 6 is a detail, partly in section, of the par- The operation of the handwheel 1 also turns, allax mechanism. through bevel gears 23, a shaft 24 which turns Fig. '7 is a plan view of the same, partly in one arm of a difierential 25 for the purpose heresection, inafter stated. Handwheel i also operates the 55 sound lag angle determining device in box 56. This is shown as accomplished through sprocket 26 and chain 21, the latter passing around idlers 21' to drive a sprocket wheel 28 on the same sleeve with a second sprocket wheel 29 geared through chain 30 to sprocket wheel 3| on shaft 32. This drive rotates the sphere 33 in one plane through bevel gears 34, shaft 35 and friction drive disc 36.

Similarly, the elevation handwheel HI turns the horns in elevation through shaft l0, bevel gears 31, shaft 38 and pinion 39, which meshes with a large gear sector 40 which turns the horns in elevation. At the same time the shaft ill of handwheel Ill revolves a chain 4| through sprocket wheel 42, said chain revolving sprocket wheel 43 on shaft 44, the shaft 44 and the sleeve 28 being coaxial with the axis of rotation of housing 50. The shaft 44 is shown as having a second sprocket 45 thereon which drives, through chain 46, a sprocket 41 on the same sleeve 48 with a friction disc 49 positioned at right angles to the disc 36, which also drives the sphere 33.

The chains 30 and 46 are shown as housed within an arm or housing 50 journaled on the side of the main box 52 at a point 53 spaced from the axis of rotation of hollow shaft or tube 5, to which tube is secured bracket 55 which is formed as a fork at its outer end and within which the box 56, containing the ball 33 and its driving mechanism, is journaled on horizontal trunnions 51' and 51'. By means of this parallel linkage, the box 56 is maintained horizontal as it is bodily revolved in elevation about the center of hollow shaft 5, arm 50 being pivoted thereto at 53'.

On top of said box 56 is mounted the pantograph linkage 58 which carries the false target or ball 22. As explained in my prior application, the inner movable point 59 of said linkage is displaced from its neutral center line directly over the center of sphere 33 an amount proportional to the estimated air speed of the target, while the direction or path of the displacement is determined by the position of the roller 60, which is driven from the ball 33, and is carried by the vertical shaft 6i which is perpendicular to both shaft 35 and sleeve 48. Shaft 6| carries at its top a U-shaped bearing frame 62, which may be made in the form of a miniature airplane 63 and within which is journaled threaded shaft 64. Threaded on said shaft is a nut 66 which carries pin 59 swivelled to the inner end of the pantograph. A knurled thumb piece 61 rotates shaft 64 to' position pin 59 for the estimated airspeed, as shown by scale 68, and the movements of the sound locator will rotate the frame 62 and, with it, the miniature airplane, so that the miniature airplane always points in the direction that the target is flying, i. e., the path or plane of displacement of pin 59 is determined thereby.

It may be shown mathematically that the gear ratios between the elevation drive to roller 43 and between the azimuth drive to roller 36 should not be the same and, in fact, for theoretically perfect results, at least one drive, i. e., the ratio of the two drives, should be varied with a function of the angular elevation cos 9?) sin For practical purposes, however, due to various factors such as sound refraction at low elevation angles and difliculty of operation at high elevation angles, the useful operating range of the sound locator is in the region of about 15 to 75 degrees elevation. For simplicity in design, therefore, in the preferred embodiment of my invention I take a meanya'me of cos {2) sin Q) as .4 and make the gear ratios such that the speed of rollers 36 is .4 that of the speed of roller 49 for the same angular velocities of the sound 10- cator in azimuth and elevation, i. e., roller 49 is designed to rotate 2.5 times as fast as the roller36.

For introducing the parallax correction, 1 adjustably fix a second point 69 in the double pantograph arrangement. At this point is a connecting pin 10 projecting from a small plate ll adjustably pivoted on top of a circular plate or disc 12, the latter being journaled in bracket 14, projecting from the box 56 by means of stub shaft 13. The plate II is shown as eccentrically piv oted at 15 to disc I2 and has a slot 16 adjacent its forward end so that it may be clamped in any position by means of clamp screw 11. An arbitrary scale 18 (Fig. 6) may be placed on disc 12, on which a reference mark 19 on plate II is read. When the reference mark is on zero, the pin 10 lies directly over the center of rotation of stub shaft 13, as shown in the figures, so that in this position no parallax correction is introduced. If, however, the plate is moved in the direction shown in dotted lines in Fig. 7, a parallax correction is introduced for the searchlight location. The direction of lateral displacement of the searchlight is introduced by turning disc I2, which has a directional arrow thereon, so that it points directly at the searchlight. This may be accomplished by temporarily depressing a pinion M which normally engages a gear 82 secured to disc 12 and turning the arrow with the fingers to the proper position, after which the gears are reengaged. The purpose of the gears is to maintain the arrow pointing at the searchlight regardless of the subsequent movements of the sound locator in azimuth. To this end, the gear 8| is driven from shaft 36 of azimuth friction disc 36, as by means of worm gearing on skew gearing 83, so that the arrow is turned in the reverse direction to the azimuthal movements of the sound locator, and at equal speed.

The effect of this parallax adjustment on the system may be seen from Fig. 8. In this figure, for the sake of simplicity, the point 59 is assumed to be adjusted for zero target speed and the target B is supposed to be very near the horizon, with the sound locator at L, the searchlight at S, and the false target at B'. Without a parallax correction, the searchlight would obviously be pointed on the dotted line SC parallel to the line LB connecting the sound locator and target. It is obvious that this beam would not strike the target, so that it is necessary to turn the beam backwardly in azimuth through an angle 6' to SB. Now draw LA parallel to SB and AB parallel to LS, and AB' parallel to AB. It will be seen,

by similar triangles, that .12 LB "LB mated, this ratio may be obtained from a table and set up on the arbitrary scale 18. With this adjustment, the ball 22 is moved from B to A, where the target, sound locator and searchlight are in line. As the sound locator is revolved in azimuth and elevation, the false target will be moved around the circle C of radius A'B'. Since, however, the false target is observed only through the sight I8 and the offset remains along arrow 89 pointed at the Searchlight, the parallax correction will be correctly applied for all positions of the target, since the points on circle C will be projected along a line connecting the eye and the ball under a similar theory of operation to that described in my prior application 88,082 in connection with the introduction of the sound lag angle correction (see Figs. 8 and 9 thereof). The result is that the parallax correction is correctly resolved into its proper components in azimuthal and elevational angles for all positions of the sound locator. There is, of course, superimposed on this motion due to parallax correction the sound lag correction due to the displacement of the point 59, as above described and more completely set forth in my prior application.

The introduction of either or both of these corrections results in a displacement of the false target 22 so that the line of sight must be read- Justed to sight on the same from the position indicated by the sound locators. This readjustment is effected, in this form of the invention, by means of a crank-knob 85. This device may be bodily revolved in azimuth to turn sleeve 86, rotatably mounted in the bottom of the housing 81, on which the sight proper is mounted. Said sleeve is shown as having an arm 96 extending therefrom, in which shaft 95 of knob 85 is journaled. Mounted on said sleeve is a gear 88 which drives a gear 89 on shaft 99. On said shaft is a pinion 9| which meshes with a gear 92 secured to the base of the sight proper. Said shaft also turns the opposite arm of the differential 25 to the drive from the handwheel 1 through shaft 24. The planetary arm of said differential operates shaft 93 so that the transmitter 94 which transmits the azimuth readings to the searchlight transmits both the azimuth movements of the sound locator and the azimuth corrections as applied from the sight.

The elevation corrections are introduced by rotating knob 85 to turn shaft 95, journaled within arm 96. The rotation of shaft 95 lowers and elevates a short vertical shaft 98 by means of a pinion 99, the teeth of which engage circular teeth I99 cut around said shaft. The vertical movement of said shaft is transmitted through similar teeth to a pinion IM and thence to an arm of the differential 25' opposite to the arm actuated through shaft I92 from elevation handwheel I9. The third arm of said differential actuates a shaft I93 which not only actuates the elevation transmitter I94 for controlling the searchlight, but also moves up and down a vertical shaft I95 through pinion I96 to move the mirror I9 in elevation about its trunnion axis 29. The difference in the drives from the two difierentials is due to the fact that the sight is rotated in azimuth with the sound locators, but not in elevation, so that it is necessary to impart to the mirror one half the entire elevational movement of both the sound locators and the correction. The movements of shaft I95 rotate the mirror about trunnion 29 through pinion I91, gears I99 and gear sector I I9 secured to the under part of the mirror support.

As hereinbefore stated, for a precise positioning of the following roller 69 at the true course angle 9, that is, the angle between the line connecting the sound locator and target and the horizontal projection of the target course (see Fig. 11) the relation is as follows:

G-tan where Va represents the horizontal component of the targets velocity (VT) in the listening plane and V1. the horizontal component normal to the listening plane. If the driving rollers 49 and 36 be driven at the same and constant ratio from the angular velocity of the sound locator (m for azimuth and for elevation), then w; i It can be shown mathematically, however, that this is not truly correct, that is, that tan K a does not always equal 6 tanbut that the true equation is 9=tan cos sin t where w is the elevation angle. Therefore I propose, as shown in Fig. 9, to insert in the drive connecting the azimuth driving roller 36 to the azimuth movements of the sound locator a variable speed drive of speed ratio characteristics cos 55 sin 53, which may also be written sin 22).

For this purpose I have Jaused the shaft 32 in Fig. 9, which is driven from the azimuth movements of the sound locator through a sprocket 3|, as before, to drive a friction disc I39 with which engages a radially adjustable friction roller I3I. Said roller is shown as splined on the shaft I 32 and having secured thereto a collar I33, so that said roller is radially adjusted from a fork I34 which engages the collar and is mounted on a cam pin slider I35. Said pin is shown as having a squared section slidably mounted in horizontal slot I36 in the casing 56'. The pin portion I35 extends outwardly and engages a curved slot I31 formed in extension I39 from the forked arm 55' which pivotally carries the box 56', as in the main form of the invention. The curved slot I31 is so shaped that the pin I35 is held in its innermost position when the arm 55' is at 45, in which position the roller I3I is driven at its maximum speed (since the sine of twice 45 is 1). The slot curves symmetrically away from pivot point 51 above and below the horizontal plane thereof so that the speed of the roller I3I, as driven from disc I30, is diminished by being multiplied by a factor sine 2% 0n the shaft I32 is shown a pinion I39 which drives a gear I49 secured to the driving roller 36", said gear and roller being rotatably mounted on the shaft 35' which drives the gearing 83 for the parallax mechanism, the shaft 35 being shown as driven through bevel gears 34 directly from the shaft 32, so that the variable speed drive does not affect the parallax mechanism.

From the foregoing the operation of my invention should be apparent. The observers first set the arrow 89 to point toward the searchlight,

fecting the illuminating range of searchlights and the type of the attacking bombers estimate the range LE and speed. The proper values are then set up on arbitrary scale 18 for the parallax correction and on speed scale 68, and as soon as the attacking plane is heard, the listeners start operating the azimuth and elevation handwheels I and III to follow the target with the sound locators, which, as explained, will position the false target 22 in line with the target. The observer through eye piece l8 maintains the line of sight on the false target, by which the proper angles in azimuth and elevation are transmitted from transmitters 94 and H14 to the searchlight or, preferably, to an intermediate or comparator station at which the binoculars are located and which retransmits the hearings to the searchlight, in accordance with the system shown in my prior joint patent with Preston R. Bassett $2 2,003,661, dated June 4, 1935, for Searchlight directors. As soon as the binocular observer sights the target, he assumes control of the transmission of angles to the searchlight.

If desired, the comparator station may be omitted and the angles transmitted directly to the searchlight. In this case, the binocular telescopes I40 are preferably mounted by the side of the eye piece I8 (Fig. 8A) and the mirror l9 lengthened so that it may be used both with the eye piece/and .the binoculars to sight the target, the binoculars being mounted on the same base 92 asthe eye piece and movable therewith. Preferably, the binoculars are positioned close enough to the eye piece so that the observer may look with one eye through the eye piece and with the other eye through the adjacent eye piece of the binocular, so that as soon as the target is sighted, he may, shift over both eyes to the binoculars and assume direct control thr'oughthe knob 85, from which the transmiters 94 and I04 are controlled. The listeners may then continue to operate handwheels I and ID, if desired, although this may not be necessary, except that it facilitates picking up the target again if lost by the binoculars.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In a sound locator for aircraft targets, the combination with sound responsive receivers mounted for turning in azimuth and elevation and a searchlight located at a distance therefrom, a sight mounted adjacent said receivers for turning movements in like planes, a spaced false target, and means for maintaining said false target in the true line of sight from said sight to the aircraft, including means for displacing said false target from the sound position line as determined by said receivers proportionally to the estimated speed of'the aircraft, means for determining the direction of such displacement from the azimuth and elevation movements of said receivers, and means for giving said false target an initial lateral displacement respectively proportional to and opposite to the distance and direction of the searchlight from the sound 10- cator, whereby the proper parallax is introduced for all positions of the sound locator.

and from their knowledge of the conditions af-- 2. In a sound locator for aircraft targets, mounted for rotation in azimuth and elevation, an adjacent sight mounted for rotation in azimuth and elevation, a pantograph spaced from the sight, means for moving the free end thereof from the movements of said sound locator, and dual means for independently adjusting the expansion of said pantograph in a horizontal plane to vary the position of a false target thereon on which said sight is trained, one of said means being positioned to correct for parallax due to the remote location of the searchlight and the other beingcontrolled by the relative variation of the angular rates of rotation of the sound locator in azimuth and elevation and the target's speed.

3. A sound locator-searchlight corrector as claimed in claim 1, wherein the initial displacement of the false target is in line with but opposite to the searchlight displacement and of an amount proportional to the ratio between said searchlight displacement and the range of the target.

4. As a means for assisting in the positioning of a false target in a sighting device for use with anti-aircraft sound locators, a sphere mounted for rotation in all planes, a drive roller for rotating it in one plane, driven from the turning of the sound locator in azimuth, a second drive roller for rotating the sphere in a plane perpendicular to said first plane and driven from the turning of the sound locator in elevation, the ratio of the drive between the sound locator and the two rollers being approximately'2.5, and means positioned by said sphere for determining the resultant plane of rotation, said false target being positioned in part by said means.

5. As a means for assisting in the positioning of a false target in a sighting device for use with anti-aircraft sound locators, a sphere mounted for rotation in all planes, a drive roller for rotating it in one plane, driven from the turning of the sound locator in azimuth, a second drive roller for rotating the sphere in a plane perpendicular to said first plane and driven from the turning of the sound locator in elevation, 2. variable speed device between at least one of said rollers and the sound locator drive, means for varying the, speed transmitted by said device in accordance with a function of the angular elevation of the sound locator, and means positioned by said sphere for determining the resultant plane of rotation, said false target being positioned in part by said means.

6. The combination with a sound locator for aircraft, of a sight and false target therefor for fixing the true line of sight from the indicated sound line, a computing device on which said false target is mounted, means for mounting said device for revolution in azimuth and elevation with the sound locator, means on said device for displacing said false target from the indicated sound line an amount proportional to the speed of the craft, means operated by the movements of the sound locator in azimuth and elevation for determining the direction of said displacement, and a second means for displacing said false target an amount for a parallax correction in the opposite direction to the direction of searchlight displacement from the sound locator.

'7. In an anti-aircraft fire control mechanism, a primary device for continuously determining by direct observation the approximate angular position of the target in azimuth and elevation, a sphere, means for rotating the sphere about one axis from the azimuthal angular movements of said device, means for rotating said sphere about another axis perpendicular to the first axis from the elevation movements of said device, a variable speed device between at least one of said rotating means and said sphere, means for varying the speed transmitted by said device in accordance with a function of the angular elevation of the sound locator, a follower positioned about an axis perpendicular to both of said other axes of rotation in accordance with the resultant direction of rotation of said sphere about said first two axes, and means positioned by said follower, indicating the direction of the path of flight of the aircraft.

8. An aircraft locating device as claimed in claim 5, in which said variable speed device varies the speed of drive of the azimuth driving roller for the sphere proportionally to the sine of twice the angle of elevation of said locator.

9. The combination with a sound locator for aircraft, of a sight and false target therefor for fixing the true line of sight from the indicated sound line, a computing device for displacing said false target from the indicated sound line an amount proportional to the speed of the craft,

means operated by the movements of the sound locator in azimuth and elevation for determining the direction of said displacement, a telescopic sight adjacent said other sight and movable therewith to facilitate sighting the real target without interference from the false target, and common means for transmitting the angular movements of said two sights to the fire control station.

10. The combination with a sound locator for aircraft, of a sight and false target therefor for fixing the true line of sight from the indicated sound line, a computing device for displacing said false target from the indicated sound line an amount proportional to the speed of the craft, means operated by the movements of the sound locator in azimuth and elevation for determining the direction of said displacement, transmitting means actuated from said sight for positioning the searchlight, and binocular sights adjacent said first named sight and adapted to actuate said transmitting means when the real target is sighted.

FRANK R. HOUSE. 

